The law regulating the relationships of lords and vassals in the period before ca. 1000
A.D. was primarily based upon unwritten customary usages. The sources from the period 800 to
1000 contain terms like lord (dominus), vassal (vassalus), fief (beneficium or feudum) that later
jurists would carefully analyze and define. Historians have learned that when they find these words
in early medieval sources, they cannot simply assume that these words describe the same lord and
vassal relationship that historians of the mid-twentieth century often used to describe the feudal
relationship in later law: a lord bestowed a fief upon a vassal in return for military service. The
vassal swore homage and fealty to the lord.

In the period from 800 to 1150, the word that described a fief (sometimes, but not always,
a piece of land) a was generally beneficium. Although the word, “feudum,” from which the English
word feudal is derived, is found in early sources, it replaces beneficium as the standard word to
describe a fief only during the twelfth and thirteenth centuries. At the same time the law governing
the bestowal of fiefs, the rights of lords and vassals, and the complicated property rights of fiefs
emerge from unwritten, ill-defined, customary chaos in which rules and principles were fluid. For
political relationships the feudal contract had several advantages over a contract in Roman law. The
feudal contract could be inherited and broken for political reasons. When a feudal contract passed
from one generation to another, the bonds that the contract cemented were renewed in public
ceremonies that reminded each party of its obligations and duties.

Law can exist without jurisprudence, but law without jurisprudence is uncertain. Unless
there are jurists to interpret the law, the rights of persons cannot be secure. Before ca. 1100 Europe
was a land without jurists and without jurisprudence. In the first half of the twelfth century the
study of law in schools began in North central Italy, especially in the city of Bologna. A professional
class of jurists began to teach, practice, and participate exercise of power in the courts of the nobility
and the governmental institutions of the Italian towns. They used Justinian’s great codification of
the sixth century Corpus iuris civilis as the text upon which they commented and with which they
taught. A man named Gratian produced a book of canon law upon which the jurists based the study
of ecclesiastical (canon) law. These books became the standard Libri legales (law books) for the
study of law, the Ius commune, in the schools and for the practice of law in the courts.

There were no books for feudal law. Because secular and ecclesiastical institutions were
involved in legal relationships that were feudal, there was a need for written law and a jurisprudence
that would provide an interpretive tool to understand it. Monasteries had feudal ties with persons
and institutions. Bishops had feudal relationships with men and towns. Towns had feudal contracts
with other towns and persons. The nobility had traditional feudal contracts with vassals but also with
towns. Feudalism had become much more than contract that regulated and defined a relationship
between a lord and a vassal. Lawyers who studied the new Ius commune at Bologna and other
schools quickly realized that texts were needed. Mid-twelfth century jurists began to organize the
study of feudal law around a diverse set of texts. The most unusual was the central role that a letter
of Fulbert, bishop of Chartres (1006-1028) played in the development of feudal law.

William V, count of Poitou and duke of Aquitaine had asked Fulbert for advice about the
obligations and duties that a vassal owed to a lord. William had troubled relationships with his
vassals. In his reply (ca. 1020) Fulbert wrote a short treatise on feudal relationships that circulated
fairly widely. Its future as a fundamental legal text was assured when Bishop Ivo of Chartres (1091-1116) placed it in his canonical collections. Gratian placed it in his Decretum (C.22 q.5 c.18) ca.
1120 where it became a locus classicus for canonistic discussions of the feudal contract and the
relationship of the lord and vassal. Fulbert told William that when a vassal took an oath to his lord
that six things were understood to be contained in it whether explicitly expressed or not: to keep his
lord safe, to protect him from harm, to preserve the lord’s justice, to prevent damage to his
possessions, and not to prevent the lord from carrying out his duties. Fulbert alleged that he got this
list from written authorities, but his exact source, if there was one, has never been discovered. For
the next four centuries jurists cited Fulbert’s list of obligations and duties as being central to the
feudal oath of fealty.

The canonists discussion of this text illustrates why feudal law became so important in the
later Middle Ages. They applied the Fulbert’s principles to the relationship between popes and
bishops, between the emperor and the pope, and between bishops and the clerics under them. The
greatest canonist of the twelfth century, Huguccio of Pisa (ca. 1190), noted that these principles
applied to the oath that the emperor and bishops made to the pope and that clerics sometimes made
to their bishops. Huguccio and later canonists concluded that if a cleric gave legal assistance to
litigants in a law case against his own church or his bishop to whom he had sworn an oath, he could
be deprived of his benefice just as a vassal could be deprived of his fief for the same offense.
Principles of feudal law were extended into relationships that had little to do with the traditional
bond between a lord and vassal. Canonistic commentaries also seem to have shaped the ethical and
moral standards that vassal had to maintain. Although they certainly drew upon unwritten customary
practices, the canonists laid down the rules in their commentaries on Fulbert’s letter that forbade
vassals from violating the sanctity of their lords’ women (wives, daughters, and other members of
the household) and from injuring their lords’ interests in court by testifying against them.

The basic books of feudal law were formed in the second half of the twelfth century. Obertus
de Orto, a judge in Milan, sent his son Anselm to study law in Bologna ca. 1154 and 1158. Anselm
reported to his father that no one in Bologna was teaching feudal law. Obertus wrote two letters to
his son (that may be rhetorical conceits) in which he described the law of fiefs in the courts of Milan.
It may be that the primary reason why Obertus wrote these two letters were the compilation of
customary law that was being undertaken by the commune of Milan. Whatever the case may have
been, Obertus’ two letters became the core of a set of texts for the study of feudal law. Obertus put
his letters together with other writings on feudal law, especially from Lombard law, to create the first
of three “recensions” of the Liber feudorum (in the manuscripts the book was named Libri
feudorum, Liber usus feudorum, Consuetudines feudorum, and Constitutiones feudorum). The
manuscripts of the first two recensions reveal that there was no standard text. Some of them
included eleventh and twelfth-century imperial statutes of the emperor’s Conrad II, Lothair II, and
Frederick I. The second recension often contained the letter of Fulbert of Chartres and additional
imperial statutes. Typical of legal works in the second half of the twelfth century the jurists and
scribes added texts of various types(extravagantes) to this recension. There are almost no two
manuscripts that contain exactly the same text. The jurists did not comment on the Liber feudorum
of Obertus. The text’s entry into the schools must have been slow. The first jurist to write a
commentary on the Liber was Pilius. He wrote a commentary on the second recension ca. 1192-1200, probably while he was a judge in Modena. He did not comment on all parts of the Liber.
Although the letter of Fulbert of Chartres circulated in many manuscripts he did not gloss it. This
illustrates an important point about feudal law in the twelfth century: its jurisprudence was not
created by one corner of the world of law.

The final or vulgate recension of the Liber feudorum added constitutions of the Emperor
Frederick II, the letter of Fulbert, and other texts that had circulated in the twelfth-century
manuscripts. Accursius, the most important jurist of Roman law in the thirteenth century, wrote a
commentary based on Pilius’ in the 1220's. It may have gone through several recensions, not all by
Accursius. Accursius also wrote the Ordinary Gloss on the rest of Roman law at about the same
time. His authority and the importance of feudal law combined to give Liber feudorum with
Accursius’ Ordinary Gloss a permanent place in the Ius commune. From the 1230's on the Liber was
included in the standard manuscripts of Roman law immediately after the Authenticae that the
stationers at the law schools produced for jurists, students, and practitioners. In the fourteenth
century Johannes Andreae († 1348) questioned whether the Liber feudorum had been legitimately
included in the Libri legales since there was no public official who mandated its inclusion in the
body of law. Johannes presented both sides of the question, but most jurists decided that it was a
legitimate text because it had been accepted by custom and the schools.

Canon law continued to contribute to the jurisprudence of feudal law after the twelfth century
but did not produce any legislation as central as Fulbert’s letter. Pope Innocent III (1198-1216)
touched upon feudal matters in many of his letters. Two of them entered the official collections of
canon law under the title De feudis. One of these letters shaped feudal law in an important area: the
right of a lord to bestow a fief when he had taken an oath not to bestow a fief on someone else.
Feudal law in the later Middle Ages found its jurisprudential roots in Roman law, canon law and in
secular legal systems. This cross-fertilization accounts for the vigor of feudal law until the end of
the sixteenth century.

The first penetration of feudal law into secular can be found at the beginning of the thirteenth
century. When the commune of Milan published its statutes in 1216 the titles that dealt with feudal
law were taken primarily from the Liber feudorum. The statutes contain an oath that a vassal took
to his lord: “I swear that I will be henceforward a faithful man and vassal to my lord. I will not lay
open to another to <my lord’s> injury what he has entrusted to me in the name of fealty..” In a
reference to the canonistic commentary on the letter of Fulbert and the presumptions of ethical and
moral rules that governed the feudal oath, the statutes added: “There are many things contained in
these words which are difficult to insert here.” When the Emperor Frederick II promulgated a law
code for the Kingdom of Sicily in 1232, the Constitutiones of Melfi, he carefully regulated the
succession of fiefs and the rules governing the nobility in bestowing fiefs. The jurists commented
on Frederick’s Constitutions and incorporated it into the jurisprudence of the Ius commune. After
the early thirteenth century many secular legal codes dealt with feudal customs in their jurisdictions.
They acknowledge a wide range of different practices. In Spain the Siete Partidas and in France the
Etablissements de Saint Louis dealt extensively with the customary law of lords and vassals.

Feudal relationships generated legal problems and court cases in the later Middle Ages. The
earliest reports of court cases involving feudal disputes and using feudal law date to the late twelfth
century, and their numbers proliferate during the thirteenth and fourteenth centuries. As the number
of these cases increased, jurists were called upon to write consilia (legal briefs) to solve them. The
jurist who best illustrates this development is Baldus de Ubaldis. He had taught for many years in
the republican city of Perugia when, in 1390, Giangaleazzo Visconti called him to the University of
Pavia. Baldus became Giangaleazzo’s court lawyer and devoted much of his time struggling with
Visconti’s legal problems and those of his vassals. Giangaleazzo was attempting to assert feudal
rights over his vassals, and to support his lord, Baldus became enmeshed in the intricacies of feudal
law. He finished a commentary on the Liber feudorum in 1393. It became the most important
exposition of feudal law in the late Middle Ages. Baldus also wrote a number of long consilia in
which he tried to give legal justification to the state based on feudal privileges, rights, and
obligations that Giangaleazzo wanted to create. Baldus found it difficult to justify Giangaleazzo’s
claims when they violated deeply embedded norms of feudal law and the Ius commune. The result
was a series of torturous and convoluted consilia whose composition betray Baldus’ ambivalence
about his task.

Feudal law remained an important part of European jurisprudence until the seventeenth
century. Jurists regularly treated feudal problems in their consilia. They also continued to write
commentaries on the Liber feudorum. The last two great commentators on feudal law were Johannes
Antonius de Sancto Georgio (†1509) and Mattheus de Afflictis († 1529) who wrote extensive and
widely circulated commentaries on the Liber.